Tobacco Smoke Filter and Methods of Making the Same

ABSTRACT

A tobacco smoke filter ( 10 ) can comprise a spiral core ( 11 ) of impermeable or semi-permeable material. A filter spiral core ( 11 ) is surrounded by filter material ( 12 ) such as cellulose acetate and wrapped in paper ( 13 ).

FIELD OF THE INVENTION

The invention relates generally to devices for filtration of tobaccosmoke, their manufacture and use. More specifically, the inventionrelates to filters suitable for use in smoking devices.

BACKGROUND OF THE INVENTION

Single-use, disposable filters have been incorporated in smokingproducts for decades. Filters are commonly made of cellulose acetate,relying on a process whereby cellulose acetate is dissolved in a solventsuch as acetone, and polymer filaments are spun out of the solution. Thefilaments are lubricated and bundled, then crimped and dried.Alternative filter materials include polypropylene and cellulose.Filters may be segmented, potentially with different materials indifferent segments; they may incorporate granular additives such ascarbon.

The filter is located at one end of the tobacco rod so that smoke fromthe burning tobacco rod, which comprises a particle phase and a vapourphase, passes through the filter before being inhaled by the user. Thefibres of the filter form a mechanical barrier which entraps particulatematter in the smoke stream. Early filters relied solely on thismechanical filtration; see for example U.S. Pat. No. 4,502,495.

More recent approaches include providing ventilation holes along thepaper wrapper outside the filter to dilute the inhaled smoke. They alsotarget the volatile constituents of the smoke, which are typicallyunaffected by the physical barrier of the filter. For example, adsorbentor absorbent materials are often added to selectively remove volatileelements from the smoke stream.

Activated carbon, porous minerals such as meerschaum, silica gel, andcation- or anion-exchange resins are frequently used as filteradditives. Carbon or charcoal can be useful for removing acidic gases.Meerschaum has a strong adsorption affinity for charged species. Silicagels readily adsorb aldehydes and hydrogen cyanide. Cation exchangeresins have been proposed for nicotine removal, while anion exchangeresins have been proposed for the removal of smoke acids. Researchersare continually developing new additives which target classes of orspecific smoke constituents.

One challenge faced with the addition of granular or particulatematerial to the filter filaments is how to adhere the individualparticles in such a way that they remain active. For example, adhesiveswhich ensure particles stay in position on fibers can block reactionsites on the particles. One solution has been to form cavities in thefilter and load them with batches of particles, although that presents adifferent problem, namely, how to channel the smoke stream through sucha loose bed of particles during use.

A further solution to containment of particles is to enclose them intubes running parallel to the direction of smoke flow, whereby the smokepasses through the tubes and contacts the particles therein. By makingthe tubes non-linear, the route of filtration is longer, see U.S. Pat.No. 4,373,539.

Other examples of known filters are disclosed in WO 86/03381, US2003/0200973, and EP-A 0033772, which describe various filters having ahelical channel for smoke.

As reducing particulate and vapour constituents in smoke remains apressing need in the art, new materials and methods for improving uponexisting filters are desired. Particularly, solutions which can be usedin conjunction with any variety of conventional or novel filtermaterials and additives would be of particular benefit.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a smokefilter for a tobacco product comprising an axially extending filtersection defining a path along which, in use, smoke passes throughfiltration material, wherein the path extends helically around the axisof the filter. By providing a smoke path that thus winds around the axisof the filter, the contact time of the smoke with the filtrationmaterial and the surface area of filtration material contacted may beincreased.

According to an embodiment of the invention, a tobacco smoke filter isprovided which comprises a generally cylindrical enclosure having aninner diameter and a helical element having a diameter and disposed inthe enclosure, where the diameter of the helical element isapproximately equal to the inner diameter of the enclosure. The filterfurther comprises filtration means disposed between the helical elementand the enclosure.

The enclosure may comprise plug wrap, which may comprise a plurality ofventilation holes. If provided, ventilation holes may be positioned tocorrespond to regions of the enclosure which do not overlie the helicalelement. The enclosure may be at least two layers, for example, an outerlayer of plug wrap and an inner layer of cellulose acetate adjoining thehelical element.

The helical element may comprise polypropylene, polyethylene, paper,carbon paper, impregnated paper or any other materials as taught hereinand may comprise a coating layer on an outer surface thereof. Thecoating layer may comprise activated charcoal, activated coconut carbon,activated coal-based carbon, zeolite, silica gel, meerschaum, aluminiumoxide, carbonaceous resin, and combinations thereof. The helical elementmay comprise compressible edges at the point where the element maycontact the inner diameter of the enclosure. Alternatively or inaddition, the central portion of the spiral core may be compressible.

The filtration means may comprise at least one material selected fromthe group consisting of cellulose acetate, polypropylene, polyethylene,gathered paper, and combinations thereof, for example, randomlyorientated cellulose acetate. The filtration means may further compriseactivated carbon, flavourant, adsorbent, or absorbent.

In one embodiment, the filtration means occupies substantially all ofthe space between the helical element and the inner diameter of theenclosure. This ensures that the smoke flowing along the helical elementmust pass through the filtration means, thereby providing goodfiltration behaviour. In addition, tight packing of the filtration meanswithin the filter imparts a solid and reassuring feel to the filter.This tight packing can be achieved by using small fibres or such-like offiltration materials.

According to another embodiment, a smoking article is provided whichcomprises a tobacco smoke filter according to the present invention.

According to another embodiment, the invention relates to a method ofmaking a tobacco smoke filter which comprises the steps of providing agenerally cylindrical helix having intra helical turn space and havingan outer edge, placing filtration means in the intra helical turn space,and enclosing the outer edge of the filled helix in an enclosure.

As used herein, “tobacco” refers to any part, e.g., leaves, flowers,stems, of any member of the genus Nicotiana and reconstituted materialsthereof. It includes derivatives such as specific compounds found innatural tobacco, e.g., nicotine, whether extracted or synthesized, aswell as structural derivatives such as the fibrous portion of a tobaccoleaf. It further includes tobacco substitutes which comprise individualchemicals and/or complex chemical entities which, when appropriatelyprepared, physically resemble natural tobacco.

As used herein, “tobacco smoke filter” means any element which isintended for use as a unit through which tobacco smoke passes and inwhich certain components in the tobacco smoke are slowed, cooled, and/orretained. Tobacco smoke includes both the by-product of tobaccocombustion and the by-product of tobacco heating in the absence ofactual combustion.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

So that the subject invention may be easily understood and readilycarried into effect, reference will now be made, by way of example, tothe accompanying diagrammatic drawings, in which:

FIG. 1 represents a perspective, partially broken away view of a filterof the invention;

FIG. 2 shows a side elevation, partly longitudinal cross-section andpartially broken away view of a filter of the invention;

FIG. 3 shows a cross sectional view of a filter of the invention takenalong lines A-A of FIG. 2;

FIG. 4 represents a perspective, partially broken away view of a filterof the invention;

FIG. 5 shows an axial cross-section view of a filter of the invention;

FIGS. 6A and 6B show two views of the element B of FIG. 5, one when afilter of the invention is uncompressed and one when a filter of theinvention is compressed;

FIGS. 6C and 6D show alternate configurations for element B of FIG. 5;

FIG. 7 is a schematic diagram of a manufacturing process according tothe present invention;

FIG. 8 shows a portion of an embodiment of a machine for producingfilters of the invention;

FIG. 9 shows a side elevation view of an embodiment of a machine forpacking intra helical space of filters according to the invention; and

FIG. 10 shows a cross sectional view taken along lines A-A of FIG. 9.

DETAILED DESCRIPTION

The invention relates to tobacco smoke filters which comprise a helicalelement centred axially therein. The element may take on any number ofconfigurations in cross-section, although it will generally be describedherein as a single helix. Referring to FIG. 1, a tobacco smoke filter 10is shown with a spiral core 11. The spiral core is provided as shown inthe embodiment of FIG. 1 with filter means 12. Spiral core 11 and filtermeans 12 are visible due to partial breakaway of the enclosure 13, heredepicted as plug wrap.

Spiral core 11 has a diameter which is approximately equal to an innerdiameter of enclosure 13. That is, the outer edges of the helixgenerally abut the enclosure. Filter means 12 is located in groovesformed by edges of the helix between spiral core 11 and enclosure 13.

As is well known to product engineers, a helix's curve can either movefrom the lower left to the upper right, making it a right-handed helix,or from the lower right to the upper left, thus being a left-handedhelix. Either right- or left- handed helices may be used as a spiralcore in the practice of the present invention.

The pitch of the helix, that is, the length of one complete helicalturn, is selected based on a balancing of the desire to increase thefiltration route with the need to permit easy inhalation. The pitch thatwill be employed with any filter according to the invention can beoptimised by a skilled worker based on variables such as material forthe helix element, particularly whether or not it is porous; materialsurrounding the helix and how densely it is packed, and ventilation,among others. The pitch might be 1-4 mm, for example 2-3 mm.

Permeability of the material used in the spiral core may preferably below in certain applications, so that it is effectively non-porous. This,combined with the placement of a less porous enclosure tightly againstthe helix, ensures that as smoke is inhaled it is forced to travel in aspiral fashion through the filter. This increases physical filtrationand provides an opportunity for additional removal of volatilecomponents from the tobacco smoke. Extruded plastics, foils or coatedpapers are some examples of materials which may be used to form thespiral core.

According to another embodiment, the material used in the spiral core isporous. Pores in the material may be formed to specifically captureselect smoke constituents. For example, the material can be polymer,molecularly imprinted with target constituents. The pores in thematerial may be impregnated with an additive such as flavourant ordiluent, which additive could be inhaled in the first few puffs duringuse leaving behind empty pores capable of interacting with subsequentsmoke streams passing there through. The spiral core may be formed ofactivated carbon, which may have a density such that the majority ofsmoke is encouraged around the helix and a minority of the smoke passesthrough the carbon structure of the spiral core. A binder may beutilized to allow granules of activated carbon to be formed into andretain the spiral shape.

According to another embodiment the spiral core is non-porous butprovided with a porous surface for interacting with smoke components.Alternatively or in addition, the spiral core may be coated, for examplewith flavourant or with an agent designed to entrap, neutralize, orotherwise interfere with smoke constituents.

The width and length of the spiral core is preferably approximatelyequal to the width and length of a standard tobacco smoke filter. Forexample, a standard cigarette filter is typically in the range of 10-30mm long and 25-30 mm in circumference. The width of the spiral core maybe less than the standard thus allowing a co-axial or multi-componentenclosure.

Where the spiral core is of firm and inflexible material, it may bepreferred to provide a region of tightly packed cellulose acetateco-axially around the outside of the spiral to cause the filter, when ituse, to more closely approximate the feel of a standard filter. Thelength may also be adjusted, for example it may be part of the length ofa standard filter to accommodate one or more filter elements on eitheror both ends.

To provide a standard looking filter it may be preferred to have afilter segment of cellulose acetate at the mouth end of the smokingarticle visible to the user, so a multiple segment filter incorporatingthe invention could be half cellulose acetate at the user end and halfnovel tobacco smoke filter at the tobacco rod end. Where the helicalelement forms only one part of a multi-element filter it may bepreferred to refrain from adding filter means within the helix.

The thickness of the material forming the spiral core is also a productvariable. Where the helix is impermeable to smoke it may be on the orderof 0.5-2 mm. When the helix is intended to be selectively permeable tosmoke constituents and/or ambient air, the thickness may be 0.5-3 mm. Itneed not be the same across the entire cross-section, for ease ofproduction or good product feel it may be that the centre of the spiralis thicker than the furthest edges. Alternatively or in addition, thecentral axis of the spiral core may be solid, forming a circle withoutwardly radiating flanges in cross section. In conjunction withmanipulation of the thickness of the material forming the spiral, pitchcan be adjusted to help provide the desired draw resistance or pressuredrop.

Ventilation holes, commonly known in the art, may be incorporated in afilter according to the invention. Such holes would increase dilution oftobacco smoke and facilitate inhalation through the circuitousfiltration path. It may be most effective to provide ventilation holesin a spiral pattern corresponding to the spiral core, at locations wherethe enclosure does not abut the edge of the spiral core. Pressure dropmay be considered when determining whether to use ventilation holes, thenumber and location being dependent on the shape and material of thehelix as well as consideration of any filter means used.

A spiral core of the present invention could be manufactured accordingto any appropriate method. Specific manufacturing requirements varydepending on the material and dimensions chosen, and on whether there isa coating on the spiral core. For example, an extruded core could beentrained in cellulose acetate during the conventional filter-makingprocess.

The spiral core and its location in relation to the enclosure causes aninhaled smoke stream to take a longer than standard, circuitous paththrough the filter before reaching the user. This provides thepossibility of increased surface area and increased time for filtrationto occur. Accordingly, the spiral core itself comprises a type offiltration means itself.

If the enclosed spiral core were surrounded only by ambient air, inhaledsmoke would not be maximally filtered as it would merely need to travela longer path prior to entering the user's mouth. The longer path wouldserve to cool the air and some particulate matter may settle out andadhere to the core or surrounding paper. Even where the spiral itselfcore comprises filtration material, and even where such a spiral core isused as one segment of a multi-segment filter, such a design fails tomaximize the opportunities to filter smoke which are available and thusmight only be preferred embodiments for special uses.

Thus, additional materials are provided in the space around the helix upto the enclosure to maximize filtration opportunities for standard uses.For example, randomly orientated acetate fibres, i.e. pieces of standardfilter material can be packed more or less tightly around the helix toprovide filtration means while still allowing smoke inhalation. Acetatefibres having any size range which allows incorporation in the filter,for example, 2 mm, could be employed.

Other options for material around the spiral core include any filtrationmaterials which are appropriate for use with filtering inhaled smoke,and may be fragments, twists, or other. The material placed around thespiral core may incorporate any number of additives such as adsorbents,absorbents, diluents, flavours, and the like. Materials and methods forincorporating them into various filter components are known in the art.For example, both activated charcoal and resins are commonly used andcould be provided.

Conventional means for producing smoking articles may be used inaccordance with the invention. Tobacco smoke filter material accordingto the invention having the same dimensions and handling properties asstandard filters can be provided to the machinery. The machinery willincorporate the novel filter with tobacco rods, wrapping paper andtipping paper to produce an article resembling conventional productsinsize and appearance but provided with a novel filter according to theinvention.

The enclosure containing the spiral core may be conventional plug wrap.It may be coated on one or both sides with any desired additive, such ascolourant and fragrance along the outer surface, to resemble a corkpattern and to have an appealing scent, and inner coating of diluent,flavourant, materials which improve filtration such as activated carbonparticles, and the like. A layer of material may be provided along theinner surface to improve the tactile qualities of the filter, forexample, a layer of cellulose acetate forming the inner diameter of theenclosure may cause the filter to feel similar to conventional filters,which may increase user appeal.

Under present manufacturing conditions, a filter portion is compressedby about 1 mm in circumference when tipping papers is added to connectthe filter element to the tobacco rod. In an embodiment of the inventionwhich is provided with a layer of cellulose acetate between the plugwrap and the spiral core the cellulose acetate layer might be able toaccommodate the compression. However, and particularly in the case ofspiral cores which directly will be directly compressed during additionof a single layer enclosure, it may be preferred to provide someflexibility or compressibility in the spiral core.

FIG. 5 depicts one example of a cross section of a spiral core 11surrounded by an enclosure 12. Circled region B is shown in more detailin FIGS. 6A and 6B. FIG. 6A shows how the edge of spiral core 11 can beconfigured in the region where it is intended to contact enclosure 12.The edge has a deformable flange-type feature which, upon compression,flexes to allow inward pressure from enclosure 12. FIG. 6B shows how theregion accommodates compression. After the compressing forces arereleased the edge of spiral core 11 re-positions itself to theconfiguration of FIG. 6A.

An added benefit of the type of configuration shown in FIGS. 6A and 6Bis that it has a sealing effect between the core and the enclosure,further ensuring that smoke inhaled through the filter is forced throughthe spiral route. Depending on the configuration and materials used forspiral core, the compressibility may also provide improved tactile feelfor the user. For example, the material used for the spiral core may beelastic and provide tension when deformed so that it re-expands to theoriginal configuration after application of the tipping paper.Alternative tipping paper application steps can be taken where, forexample, it would be economically preferred or where spiral cores areprovided which are not designed to be compressible.

Alternatively, the spiral core may be compressible. Preferably it isalso expandable so as to return to its original size after compression.Such an embodiment may be provided with rounded edges along the portionof the spiral core that is-in contact with the enclosure to avoidpuncture or tearing during compression or handling, see FIG. 6C. Anotheralternative would be to provide a flattened edge which flattened portionsits flush with the enclosure, also reducing the risk of tearing andpossibly also improving the sealing effect and tactile feel, see FIG.6D.

One method for manufacturing a filter according to the invention isrepresented schematically in FIG. 7. A device 70 comprises a spiralmaterial supply 71 which could be a bale of extruded plastic helix. Afilter means supply 72 could be a batch of cellulose acetate fibres. Anenclosure supply 73 provides means for enclosing the filter components,and could be a roll of plug wrap.

While standard methods typically produce filter materials as a longcylinder which is cut into smaller units for individual use, it may bethat certain spiral cores are advantageously made unit by unit thenincorporated into a filter and joined to a tobacco rod. They may formthe entire length of the filter region, alternatively they may be partof a multi-segment filter.

In use, device 70 feeds spiral material from supply 71 to a filter meansaddition area 74. Therein materials from filter means supply 72 areprovided to the spiral. An additive application means 75 is provided,which could be a single means as shown or a series of means, potentiallyeach supplying a different additive. A drying means 76 is provided whichmay cure the inner filter components prior to or after addition ofenclosure from enclosure supply 73. A cut off 77 is situated to cutprepared filter material to the desired length.

Any known or developed alternative methods could be used to produce atobacco smoke filter according to the invention. For example, as shownin FIG. 8 a multi-segment filter is being produced. A continuous rod 81is shown, which is intended for eventual division into a plurality ofindividual filter units 82. Each filter unit 82 comprises a first filtersegment 83, a second filter segment 84, and a third filter segment 85.In the embodiment shown, the spiral core portion is provided in secondfilter segment 84.

Particles 86 are added to the spiral core of second filter portion 84 bya dispensing means 87. Particles 86 could be filter means, additives, ora mixture of the two. One option for an embodiment such as that shown inFIG. 8 would be to have a first filter segment of cellulose acetate, asecond filter segment of non-porous spiral provided with flavourants inthe intra-helical space, and a third filter segment comprising carbonsuch as a cavity filter filled with carbon particles or carbon paperformed into a filter segment. As should be evident to the skilledperson, there are a plurality of existing methods which could beemployed similar to the dispensing means of FIG. 8.

It is contemplated that a plurality of dispensing means could beprovided to the same rod, wherein each would supply a different materialto the spiral core. For- example, a first means supplying a firstflavourant, a second means supplying an absorbent, and a third meanssupplying a second flavourant. The three means could be provided side byside to fill separate regions of the same spiral core with respectiveadditives; alternatively they could be adding their respective materialsthroughout each spiral core one after the other.

Where spiral cores are designed such that differential smoke travelpaths are observed, one or the other of these configurations may bepreferred. For example, where it is observed that the beginning portionof an inhaled puff of smoke travels primarily along the central regionof the core and the latter portion of the same puff travels along theouter regions of the core, toward the enclosure, a multi-step ormulti-layer fill might be preferred to provide first materials that willaffect the beginning portion of a puff and second materials that willaffect the latter portion of a puff.

A further example is shown in FIG. 9, where a spiral core 11 is passedthrough a rotating feeder 91 which simultaneously provides material 92around the core and provides for containment of the filled core in anenclosure 13. A cross-section along lines A-A is shown in FIG. 10, whereit is evident that material 92 is passed into feeder 91 and fills anyspace present around core 11.

While addition of filter or additive material to the spiral core afterformation may be a preferred method for certain placations, wherematerials and design allow a single process step could handle allfunctions. For example, a rotating head could extrude a spiral corewhile simultaneously filling the intra-helical space with filter and/oradditive material. A plurality of materials may be mixed first thenadded as a mixture, alternatively there could be one or more streams ofeach additive fed discretely. This latter form may be preferred wherethe added materials handle differently or where settling or otherproblems occur in a mixture.

Although FIGS. 7-10 relate to a single line for working with spiralcores of the present invention, it should be apparent to skilled personsthat manufacturing efficiencies may best be met by providing a pluralityof units or a series of steps in parallel. For example, the means shownin FIGS. 9 and 10 could be provided in duplicate or triplicate, thusproducing two or three times as much filter material as would otherwisebe made.

Example 1 Filter Manufacture

Activated carbon is moulded into a helical shape approximately 6 mm indiameter. An average pitch and low porosity, i.e., low permeability, areused. The carbon is cut into lengths of approximately 20 mm. Units ofstandard cellulose acetate tow approximately 6 mm in diameter andapproximately 10 mm long are provided and arranged in alternatingfashion with lengths of carbon helix.

The intra helical space of the carbon helix is provided with a mixtureof flavourant and adsorbent before the length of helix/cellulose acetatetow is wrapped with an approximately 0.5 mm thick layer of celluloseacetate about its circumference. Plug wrap may optionally be providedaround the cellulose acetate layer as known in the art.

This provides a length of filter material which may be cut along themiddle of the approximately 10 mm lengths of cellulose acetate tow toprovide a plurality of filter units each approximately 30 mm in lengthand each comprising an approximately 5 mm cellulose acetate tow ateither end, surrounding a carbon helix with additives in the intrahelical space.

The filters thus produced may be incorporated in smoking articles, forexample cigarette holders or water pipe mouthpieces, to provide aneffective yet disposable filtration material for the smoke inhaledtherethrough. Different lengths and thicknesses can be provideddepending on the expected use. For uses with slightly flattenedmouthpieces, the spiral core may be formed to have a slightly oval shapein cross-section. This would be regarded as still having a generallycylindrical shape as taught by the present invention.

Example 2 Cigarette Manufacture

A resin commonly used in tobacco smoke filters is extruded through a dieto produce a tight helical shape approximately 7 mm in diameter and 10meters long. The shape is fed into a machine which applies suction orvacuum, for example a suction garniture, to pack fibres of celluloseacetate around the helix. The packed helix is wrapped in plug wrap andcured on a drying garniture. The cured filter is cut to 60 mm lengthswhich are provided to a cigarette making machine.

The cigarette making machine uses the filter to produce cigarettesaccording to known methods. In brief, two tobacco rods are positioned ateither end of the filter and, once secured, the filter is cut at themiddle. An optional end segment, for example, a pad of celluloseacetate, is added at the mouth end of the cigarette to mask the helicalcore unit. The resultant product is a cigarette incorporating a noveltobacco smoke filter according to the invention.

The foregoing description and examples have been set forth merely toillustrate the invention and are not intended to be limiting. Sincemodifications of the described embodiments incorporating the spirit andsubstance of the invention may occur to persons skilled in the art, theinvention should be construed broadly to include all variations withinthe scope of the appended claims and equivalents thereof.

1. A tobacco smoke filter comprising: a generally cylindrical enclosurehaving an inner diameter; a helical element having a diameter anddisposed in the enclosure, wherein the diameter of the helical elementis approximately equal to the inner diameter of the enclosure; andfiltration means disposed between the helical element and the enclosure.2. A tobacco smoke filter according to claim 1, wherein the enclosurecomprises plug wrap.
 3. A tobacco smoke filter according to claim 2,wherein the plug wrap comprises a plurality of ventilation holes.
 4. Atobacco smoke filter according to claim 3, wherein the ventilation holesare positioned to correspond to regions of the enclosure which do notoverlie the helical element.
 5. A tobacco smoke filter according toclaim 1, wherein the enclosure is at least two layers.
 6. A tobaccosmoke filter according to claim 6, wherein the enclosure is an outerlayer of plug wrap and an inner layer of cellulose acetate.
 7. A tobaccosmoke filter according to any preceding claim, wherein the helicalelement comprises polypropylene, polyethylene, paper, carbon paper, orimpregnated paper.
 8. A tobacco smoke filter according to any precedingclaim, wherein the helical element comprises a coating layer on an outersurface thereof.
 9. A tobacco smoke filter according to claim 8, whereinthe coating layer comprises activated charcoal, activated coconutcarbon, activated coal-based carbon, zeolite, silica gel, meerschaum,aluminium oxide, carbonaceous resin, and combinations thereof.
 10. Atobacco smoke filter according to any preceding claim, wherein thehelical element is in contact with the inner diameter of the enclosure;the helical element is laterally compressible; and the helical elementmaintains contact with the inner diameter of the enclosure aftercompression.
 11. A tobacco smoke filter according to any precedingclaim, wherein the filtration means comprises at least one materialselected from the group consisting of cellulose acetate, polypropylene,polyethylene, gathered paper, carbon, and combinations thereof.
 12. Atobacco smoke filter according to claim 11, wherein the filtration meanscomprises randomly orientated cellulose acetate.
 13. A tobacco smokefilter according to any preceding claim, wherein the filtration meansfurther comprises flavourant, adsorbent, or absorbent.
 14. A tobaccosmoke filter according to any preceding claim, wherein the filtrationmeans occupies substantially the entire space between the helicalelement and the inner diameter of the enclosure.
 15. A smoking article,comprising a tobacco smoke filter according to any of claims 1-14.
 16. Amethod of making a tobacco smoke filter, comprising: providing agenerally cylindrical helix having intra helical turn space and havingan outer edge defining a generally cylindrical shape; placing filtrationmeans in the intra helical turn space; and enclosing the outer edge ofthe filled helix in an enclosure.